Transparent distributor cap



Aug. 24, 1937. w. SHERMAN" TRANSPARENT DISTRIBUTOR CAP Filgd Jan. 18, 1936 2 Sheets-Sheet 1 INVE TOR W w BY 1M Aug. 24, 1937. w SHERMAN 2,090,645

TRANSPARENT DISTRIBUTOR CAP Fiied Jan. 18, 1956 2 Sheets-Sheet 2 INVENTOR BY I 1M9 ATTORNEY Patented Aug. 24, 1937 UNITED STATES PATENT OFFIQE TRANSPARENT DISTRIBUTOR CAP sylvania Application January 18, 1936, Serial No. 59,674

4 Claims.

My present invention relates to, a. novel construction and arrangement ofa transparent cap for distributors'for the'ignition. systems of internal combustion engines.

I have-heretofore proposedmaking the cap of a single piece of glass with. integral projecting knobs to receive the terminals of the contacts. Due to the'shrinkage of the glass during cooling, difficult? manufacturing problems arise in the making of a one piece cap of this character, since to obtain the best: results, the contacts electricallyconnectedtd the spark plugs of the engine cylinders, should equally. be spaced from the high tension contact electrically connected with the high:tension.coil.. If: this is not done, a variable spark gap is. provided. for different engine cylinders, and theproper ignition of the explosive mixture in. the engine cylinders is not obtained.

The object therefore of this invention is to devise a novel distributor cap, preferably of glass,

in sections or in one piece which can be economically and accurately molded, and assembled at a minimum cost.

Qther novel features of construction and advan- 5 tage; will hereinafter clearly appear in the de- .tailed;description and the appended claims.

For the purpose of illustrating the invention, I have. shown in'the accompanying drawings preferred embodiments thereof which in practice will ggigivesat-isfactory and reliable results. It is, however; tobeunderstood that these embodiments are typical only. and that the various instrumentalities ofzwhi ch my invention consists can be variously arranged and organized and the invention is not limited tothe exact arrangement and organization of these instrumentalities as herein set forth.

Figure 1' is a top plan view partly broken away of a transparent distributor cap embodying my invention.

Figure 2 is a: top plan view partly broken away of another embodiment of my invention.

Figure 3.is a section online 33 of Figure 1.

Figure 4 is a section on line 44 of Figure 2.

Figure 5 is a side elevation partly broken away of. another embodiment of my invention.

Figure 6 isa. section on line B-6 of Figure 5.

Figure '7. is a top plan view on an enlarged scale 0 of a: portion: of the body portion and its contact receiving aperture.

Figure-8 is a partial section showing on an enlarged scale a contactv in its aperture.

Figure 9 is a section on line 9.9 of Figure 8.

Figure 10'is a topplan view of another embodiment of my invention in which the top cap or cover has been eliminated.

Figure 11 is a section on line HH of Figure 10.

Figure 12 is a bottom plan view of a portion of the cap.

Figure 13 is a sectional detail on an enlarged scale of a contact and a portion of the cap.

Similar numerals indicate corresponding parts.

Referring to the drawings:

I designates a body portion molded preferably of glass and which is internally chambered as at 2 and which has a closed top wall as at 3. The top wall 2 has molded in it contact receiving apertures which at their lower ends have a circular wall 4 and a flat wall 5, in other words are half round while at their upper portions they are conical or flare outwardly as at 6. The purpose of this is to prevent relative rotation between the contacts I, electrically connected with the spark plugs of the engine cylinders, and the body portion. The contacts I are shaped to fit the apertures in the top wall having a rounded side 8 and a flat side 9 near the lower ends, and a conical portion l0 at their upper ends, so that the contacts are accurately seated and positioned in their apertures and have their lower ends extending into the chamber 2 in which they are circumferentially spaced from each other. The fiat faces of the contacts 1 preferably are disposed towards the center of the chamber 2 to form elongated surfaces to cooperate with the distributor arm II. The contacts at their upper ends have the upwardly projecting pins or points I2.

The top wall of the body portion has molded in it half roundgrooves [3 opening through its periphery and leading to the different apertures which receive the contacts for the engine cylinders.

When the conductors M for the engine cylinders are placed in their proper grooves the points or pins l2 penetrate the conductors to make electrical connection with the wires of the conductors.

The conductors and contacts are retained in assembled position by the pressure of a transparent cap l5 against them.

The cap and body are retained in assembled position by the high tension contact !6 having an enlarged head ii and the top wall of the chamber 2 may be recessed, if desired to receive the head IT. The high tension contact extends through a central aperture i8 in the cap and is threaded to receive a nut 19 which retains the cap and body portion.

The upper end of the high tension contact it extends above the cap and receives the socket 2G for the high tension Wire 2| from the high tension coil.

The cap may have'an annular depending flange E2 on its under face to engage the conductors as shown in Figure 3, or it may have half round grooves 23 moulded in it to register with the grooves in the top wall of the body portion as shown in Figure 4.

The cap is preferably provided with a depending annular lip 24 at its outer periphery which extends into an annular groove 25 of the body portion.

In assembling the distributor cap the contacts 7 are dropped into their apertures in the top wall of the body portion. The conductors are placed in their proper grooves. The high tension contact is inserted through the body portion and cap and the nut. l9 applied to draw the cap and body portion together. This securely holds the conductors in place, and the contacts I in their proper positions and in electrical connection wit. the contacts.

The body portion may have lugs cast on it or depressions cast in it as at 25 toreceive the conventional spring clips to retain the distributor cap in assembled position on the. distributor.

In some cases these clips engage a split ring 2'3 on the outer wall of the body portion and in such case the body portion preferably has an annular bead 28 cast on it.

Since the body portion and cap or cover are of transparent material such as molded or pressed glass, the working conditions of the distributor and also of the condenser of the ignition system can be visibly determined.

Short circuiting is overcome since water will flow off of the cap without coming into contact with the contacts, since the transparent cap preferably overhangs the body portion or is flanged to seat in a recess or groove below the top face of the body portion.

I have found in practice that if the contacts I are cemented in place, they are liable to become loose after they have been in use; and if they are cast in the body portion due to uneven shrinkage of the glass they are in many cases incorrectly positioned when the glass cooled.

This defect in prior methods is overcome by my present invention, and therefore the production of a large percentage of seconds or parts which cannot be used and which materially increases the cost of manufacture of a glass article of this character.

If one of the contacts 1 is burned or damaged, it can be readily replaced by unskilled labor as 'all that one has to do is to remove the transmaterial, such as glass.

parent cap from its body portion, replace the damaged contact and secure the transparent cap on its body portion.

The high tension contact contributes to retain the parts in their assembled condition.

Referring now to Figures 10 to 13 inclusive, I have shown in these figures a preferred form of a transparent cap in which the top cover or cap is As illustrated, these apertures are round at their upper portions and rectangular at their bottom portion to prevent the contacts 33 from rotating. These contacts 33 have the contact portions in the chamber 30 flattened on one side or half round in cross section, with rectangular shoulders 34 and the threaded shanks 35 which extend above the cap to receive conductor receiving terminals 36. These terminals consist of non-conducting tubular members having threaded sleeves 37 secured therein. 7

The high tension contact 38 is interlocked with the top of the glass cap in a similar manner and retained in place by a terminal 39 to receive the high tension conductor from the coil.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A distributor cap, comprising a chambered body portion having a closed top with circumferentially spaced contact receiving apertures, removable contacts interlocking with the walls of said apertures to prevent relative rotation with the body portion and having points to penetrate conductors, a cap above the conductors, and a high tension contact extending from said chamher through said body portion and cap and con tributing to cause the cap to press the conductors towards said cap to retain the contacts of the conductors in assembled and interlocked condition with the body portion.

2. A distributor cap, comprising a chambered glass body portion having a closed top with circumferentially spaced contact receiving apertures having a portion half round in cross section, removable contacts having half round portions to engage the walls of said aperture and having points to penetrate the conductors, a cap, a high tension contact extending from said chamber through said body portion and cap, and means adjustable on said high tension contact and engaging said cap to retain said conductors and their removable contacts in assembled condition in the body portion.

3. A glass distributor cap consisting of a chambered body portion, and a cap, said body portion having a closed top with circumferentially spaced apertures, conical at their upper ends and half round at their lower portions and extending into said chamber, removable contacts shaped to conform to said apertures and having conductor penetrating points, said body portion and cap having registering grooves to receive conductors and extending from the apertures through the sides of the body portion and cap, a high tension contact extending from said chamber through said body portion and cap, and a nut for said contact to retain the cap against the conductors and thereby retain the conductor removable contacts in the body portion.

4. A glass distributor cap, consisting of a chambered body portion and a cap, said body portion having an outer bead and its outer wall tapering rearwardly from said bead, having a closed wall with contact receiving apertures, removable contacts in said apertures having conductor penetrating points, the cross sectional area of said apertures and contacts preventing rotation of the contacts, a high tension contact contributing to retain the cap and body portion in assembled condition, and a member surrounding said body portion adapted to receive the conventional distributor clips for securing the body portionto the distributor.

WILLIAM SHERMAN. 

